Okay Mark, I was kidding about wash your windows - maybe I should have included a ;-), but I thought you would get it. I understand that a number of people have a problem with antialiasing - usually caused by a mismatched setting. I took Mark Palmos' file and opened it and duplicated his setup. The result can be seen at:
http://www.sjon.org/xfer/LT/LT.html
By definition, the animation codec that LT uses has 256 shades of transparency which eliminated the blocking or aliasing I see in Mark's project. I still say some setting does not match. The version I loaded wasn't even rendered. My best guess is that his video format is set to 4:3 rather than 16:9, even though he has it set for HD.
Sjon